Carburetor



Jan. 19, 1932. *i F, H p, BEA-[50N 1,841,778

` CARBURETOR Filed Aug. 20, 1928 TH/22,5547 L20 i770 yal Patented Jan. 19, 1932 PATENT OFFICE FRANCIS HENRY :EATON BEATSON, OF FAISLEY, SCOTLAND CARBURETOR Application filed August 20,

My invention relates to improvements in mixture supply systems of internal combustion engines and has for its object the provision of means whereby greater economy 5 of fuel consumption andincre'ased engine eiiiciency can be obtained as compared with that possible with known mixture supply systems. f l

in the running of internal combustion en- 10 gines it is found that the greatest economy of fuel consumption and the highest eiiiciency of manipulation of an engine is obtained when temporary enrichment of the normal mixture is effected when the throttle is opened or being opened from or to any position, sustained enrichment of the normal mixture is etected during a period of acceleration of the engine, temporary weakening of the normal mixture is effected when the throttle is j?) closed or being closed from orto any position, sustained weakening of the normal mixture is eilected during a period of deceleration and complete cessationl of fuel tlow ensues during a period of extreme deceleration. Ars used here the term normal ,mixture means a mixture strength less than "that necessary for maximum power and refers 'to the ratio of fuel to air and not to any particulaix volume of flow. i' .4 l lThis invention consists in an improved mixture supply system of.;an internal combustion engine and comprisesv means'responsive to any change of depression produced by the engine suction and adapted automatically to vary temporarily a normal strength in order that the system after disturbance shall deliver a normal mixture when the depression is unchanging that is to saywhen the engine output and load arein equilibrium. ln order that the invention may be better understood l will now proceed to describe the same in relation to the accompanying drawings reference being had to the letters` and figures marked thereon; like letters refer tolike parts in the various figures in which Fig. 1 is a diagrammatic view showing the invention applied directly to a valve in the fuel conduit fromv the float "chamber to the r jet orifice of a carburetor whereby the mix- 50 ture strength may be varied.

1928. Serial N0. 300,829. I

Fig. 2 is a diagrammatic view showing a modilied form of the invention without any mechanical moving parts applied to a carburetor.

ln Fig. 1, 9 represents the body of a car- 5x5 buretor, 1 the float chamber, 6 the jet, 9X the throttle valve, 8 the throat rof the suction chamber, 21 a fuel valve and 22 the seat therefor.

The throat 8 of the carburetor 9 is providtu ed with an aperture 8X connected by a conduit 26 having two branches 24 and 27 with the diaphragm chambers 12 and 13 respectively.

rlhe valve 21 is mounted on a stem 14 at 65)'A tached to and adapted to he operated by a flexible diaphragm 11 forming a partition between the chambers. 12 and 13. rlhe stem 14; above the diaphragm 11 is provided with a spring 1'? and the stem 11i below the diao phragm 11 is provided with a spring 18, the springs 17 Iand 18 oppose each other and reacting against ixed parts of the chambers 12 and 13 maintain the diaphragm 11 in a normal position and state of equilibrium. With the i5 diaphragm 11 in the normal position the uel valve is adjusted for a dow o1'E fuel to give the normal mixture.

The upper end of stem 14 is adapted to abut against a spring stop 16 upon a definite 39V upward movement in order that the force, resisting movement of the stem 14 shall be increased when the displacement upward of the stem 1liexceeds' this dente upward movement. A

The conduit 26 is provided with a constriction 28 located betweenthe branches 2d and 27 for purposes of creating a temporary diterenceo pressure betweenthe chambers 12 and 13 u on a change of depression in 90 the suction c amber.

In use, theapparatus illustrated in Fig. 1, functions in the following manner :--If, at any given speed the engine is running on a steady load and the throttle is only partly 95 open, then a depression of a certain value will occur at the throat 8 and said depression will be communicated through the conduit 26, 24 and 27 to the chambers-12 and 13 regardless of thel value of this depression Sli lchamber 13 owing tothe constriction 28 rolonging completion in the chamber 12 o the depression and the diaphragm 11 will move upwards thus moving the fuel valve 21 into closer proximity with the seating 22 and so ,temporarily reducing the flow of fuel to the jet6 and thereby temporarily reducing the normal mixture strength until, due to the leakage past the constriction 28, the pressure in the chamber 12 is again equal to the pressure in the chamber 13 when the diaphragm 11 will again be in its normal position and state of equilibrium and the normal .mixture again effective regardless of the new Avalue of depression 4in the suction chamber.

If on the contrary, the throttle valve 9x iis shghtly opened then the fuel valve 21 is depressed and the flow temporarily increased therebytemporarily increasing the normal mixture strength. Y

Thus, it will be seen, that for any given engine speed and position of the throttle valve 9x and regardless of the value of depression provided that the load is steady'thel normal sup ly of fuel to the jet is not alectedI but if the t rottle valve 9x is opened and the engine accelerates then the depression at the throat will be increased and the diaphragm 11 will temporarily 'be moved downwards thus moving' the valve 21 away from its seating 22 and permitting a temporarily increased supply of fuel to be fed to the jet 6 and similarly,'if the throttle valve 9x is partially closed and the engine decelerates then the diaphragm 11 will raise the valve 21 into closer proximity with the seating'22 ,thus temporarily reducing the supply of fuel to the jet 6.

In the event of a substantial closure of the throttle valve 9* being suddenly effected the diaphragm 11 moves upward with considerable rapidity the end of the stem 14 coming into contact with the spring stop 16.y If the change of depression at the throat 8 is only a certain amount (which is dependent upon the deceleration introduced) the up- 'necessary to provide a stable firing mixture but -if the change of depression at the throat 8 is more than a certain amount (incidental to a large deceleration) then the u ward.

force on the diaphragm 11 will be -suliicient to overcome the resistance of the spring stop 16 and the stem 14 will move upwards a fur- A thetemporary difference between the negative pressures in the chambers 12 and 13 shall bev sufliciently large to effect the required purpose and shall not be so small in area as to introduce an undesirable degree of lag in equalization of the pressure in the chambers 12 and 13.v

The arrangement hereinbefore recited describes a methodfor temporarily varying a normal mixture strength b directly control- ,ling the flow of fuel to the )et 6 by means of a fuel valve 21. yObviously, any other means may be provided whereby the quantity of vfuel delivered -to the suction chamber or the mixture strength may be controlled in` accordance with this invention. I

In the alternative form of application illustrated in Fig. 2, I- substitute a chamber 29 which opens into the passage 7 in lieu of the parts used in the construction as illustrated in Fig. 1, and hereinbefore described. 31 is a restricted throat`formed to control the. rate of fuel flow to as Well as from the Achamber 29 into the conduit. The entrance from the float chamberll to the conduit 7 also has a restriction 32 for a particular purpose as shall be hereinafter explained. In

preparing this alternativectype of carburetor for functioning, part of the air is exhausted from the chamber 29, and its place is taken by liquid fuel which of course communicates contained in the conduit 7.

In Fig. 2.w herein moving arts are 'bviated, the air is partially ex austed from the chamber 29 which will permit the entrance of liquid fuel thereinto to take its place, as illustrated in Fig. 2. \This contained liquid fuel will be held in suspension in such chamber 29 due to the exhaustion of the air and when the fuel is flowing to the jet 6 from the float chamber 1 to give a normal mixture the carburetor will be, what I would call, in equilibrium, such normal mixture being defined by the orifice 32 connecting the ioat chamber 1 to the conduit 7. If the throttle is partially closed the depression inthe .air suction chamber 9 'becomes less and conse- Vrpliently this reduction ,of air pressure upon e liquid fuel in the jet will permit the entrance of a further quantity of liquid fuel into the exhausted chamber 29 thus momentarily weakening the normal mixture. If on the other hand, the throttle valve is slightly opened the pressure within the air suction .through the throat 31 with the liquid fuel member 9 will be decreasedwhich will cause the expulsion of liquid fuel from 'the chamber 29 to the conduit 7 thus momentarily enriching the normalmixture.

` The principle of this alternative construction is; when the engine is running at a steady speed and load the air pressure within the top of the chamber 29 is substantially equal to that of the pressure within the air ,suction chamber, so that decreased pressure in the air suction member causes the expulsion of liquid fuel from chamber 29, and an increased pressure in the air suction chamber causes the entrance of liquid fuel into the air chamber 29.

f lt can thus be seen that in both these applications a predetermined normal mixture is unaffected by any value of steady depression in the suction chamber and is only temporarily affected upon any change of depression in the suction chamber.

What l claim as my invention is `l. ln combination with a carburetor having a suction member and a fuelreservoir communicating therewith, a fuel control valve, and means temporarily actuated by a change of pressure in the suction member for actuating the -valve.

2. ln combination with a carburetor having a vsuction member and a fuel reservoir communicating therewith, means for controlling the liow of vfuel to the suction member, an oscillatable pressure actuated member having a xed axis of oscillation, conduits forming a communication from each side of the oscillatable member to the suction member whereby such oscillatable member is actuated by the varying pressure in the Asuction member, and a movable connection between the oscillatable member and the fuel flow control means.

3; In combination with a carburetor having a suction member and a fuel reservoir communicating therewith, means for controlcommunicating therewith, means for controlling the flow of fuel to the suction member, an airtight housing, an oscillatable diaphragm having 'a iixed axis of oscillation, said diaphragm extending interiorly across said housing so that a pair of chambers are constituted therein, conduits extending from the chambers to the suction member whereby the diaphragm is actuated by the varying pressure in the suction'member, and a connection extending. from the diaphragm to the fuel dow control means.

4. ln combination with acarburetor having a suction member and a fuel reservoir ling the iiow of fuel to the suction member, an airtight housing, an oscillatable diaphragm 'having a xed axis of'oscillation, said diaphragm extending interiorly across the housing' so that a pair. of chambers are constituted therein, conduits extending from the chambers to the suction member, a passage communicating between the conduits,

means for restricting the fluid iow through the passage whereby the fluctuations in pressure in the suction member are retarded in their communication with one of said chambers, and means connecting the diaphragm to the fuel low control means.

5. In combination with a carburetor having a suction member and a fuel reservoir communicating therewith, means for control` ling the iiowof fuel to the suction member, an airtight housing, a diaphragm extending interiorly across the housing so that a pair of chambers are constituted therein, and resilient means for retaining the diaphragm in normal position and state of equilibrium, conduits extending from the chambers to the suction member, a passage between the conduits, a restriction in said passage whereby fluctuations in pressure in the suction member are retarded in their communication with one of said chambers, and movable means extending from the diaphragm to the fuel flow control means.

6. ln combination with a carburetor having a suction member and a fuel reservoir communicating therewith, means for controlling the iiow of fuel to the suction member, an airtight housing, a diaphragm extending interiorly across the housing so that a pair of chambers lare constituted therein, resilient means for normally retaining the diaphragm in equilibrium, resilient means to additionally oppose movement of the diaphragm in one direction, conduits extending from the chambers to the suction member, a restriction whereby fluctuations in pressure in the suction member are retarded in their communication with one of said chambers, and connecting means between the diaphragm and fuel flow control means.

7. The combination with a carburetor having a suction member adapted for connection to the intake of an internal combustion engine and a fuel reservoir in communication through a passage with the suction member,

- means associated with said passage and responsive to the suction of the engine for supplying fuel commensurate to the varying speed requirements of the4 engine, means for augmentin the flow of fuel through said passage throng out any accelerating period, and means for reducing the iiow of fuel through said passage throughout any decelerating period, bothof said means becoming inoperative immediately following acceleration or deceleration.

8. AThe combination with a carburetor having a suction member adapted for connection to the intake of an internal combustion engine, a throttle valve within the suction member, and a fuel reservoir, in communication through a passage with the suction passage, means associated with said passage and relos sponsive to the suction of the engine for supthe pressure within the lsuction member,

plying fuel commensurate to the varying speed requirements ofthe engine,rmeans as t e throttle is opened from one position to another for roviding a constant lncrease to the flow of uel through said passage above the normal flow due to engine suctionz means as the throttle is moved from one position to a position of greater closure for providing a constant decrease to the flow of fuel through said passage below the normal flow due to engine suction, and means responsive to an abnormal closure ofthe throttle for temporarily stopping the flow of fuel through said passage.

' 9. The combination with a carburetor having a suction member adapted for connection to the intake `of an internal combustion engine, such suction member being subject to varying preures according to engine usage, a fuel reservoir in communication with the suction member through a passage, means associated with said passa e for deliverin a normal flow of fuel to t e suction mem r commensurate with the varying requirements of the engine, means for roviding throughout an entire period of ecreasing pressure in the suction member, an increase to the flow of fuel throughthe passage above the normal flow due to engine-suction, and means for providing throughout an entire period of increasing pressure in the suction member, a decrease to the flow of fuel through the passage below the normal flow due to engine suction:

10. The combination with a carburetor having a suction member and afuel reservoir in communication therewith adapted fdr connection to an internal combustion engine, said suction member being adapted to receive air for incorporation with fuel from the reservoir to forma normal gaseous mixture, a normally positioned reciprocator element having opposing sides which are ]ointly exposed to the pressure within the suction member,

means associated with said reciprocatory element for controlling the fuel-ratio to air in the suction member, and choke means interposed between opposite sides of the reciprocato element whereby a change in the velocity of mixture flow through the suction to form a normal gaseous mixture, a normalmember temporarily unbalances the pressure on opposite s1des of the reciprocatory element and rough said control means temporarily means associated with said reciprocatory element for controlling the fuel ratio to air in the suction member, and choke means interposed between .opposite sides of the reciprocato element whereby a ch velocity of mixture flow through t e suction member tem rarily unbalances the pressure on op ite s1des of the reciprocatory element and t rough said control means temporarily increases or decreases the ratio of fuel to air in the mixture, said reciprocatory element returning to its normal position when the mixture flow through the suction member becomes stable.

12. The combination with a carburetor having a suction member anda fuel reservoir in communication therewith adapted for connection to an internal combustion engine, said suction member being adapted to receive 'air' for incorporationwithfuel from the reservoir to form a normal gaseous mixture, a normally positioned reciprocator element having opposing sides which are Jointly exposed to the lpressure within the suction member, means associated with said reciprocatory element for controlling the fuel ratio to air in the suction member, and choke means interposed between opposite sides of the reciprocato element whereby a' change in the velocity of mixture flow through the suction member temporarily unbalances the pressure on opposite sides of the reciprocatory element and through said control means templrarily increases or decreases the ratio of el to air in the mixture, said fuel ratio variation being sustained throughout the period of change from one velocity flow through the suction member to another.

Signed at the city of London, England, this 30th day of June, 1928.

` FRANCIS HENRY PATO BEATSON.

increases or decreases theV ratio of fuel to air in the mixture.

in communication therewith adapted for connection to an internal combustion engine, said suction member being adapted to receive air Vfor incorporation with fuel from the reservoir .ly positioned V recip'roca'tor element having 6.5 'opposing sides which are jointly exposed to in thel lasl 

